Research & Pricing Methodology
A transparent framework for technical claims and time-sensitive market observations
This page explains the evidence standards we use when building and updating AsscherDiamond.com. It is designed to prevent a common problem in diamond content: precise-looking recommendations that are presented without showing where they came from.
Evidence classes
| Label | Required support | Allowed wording |
|---|---|---|
| Primary-source fact | Direct support from a grading laboratory, standards body, or clearly identified first-party historical source | May be stated as fact within the source's scope |
| Editorial screening range | Clearly identified as AsscherDiamond.com guidance; not presented as a lab standard | “Starting point,” “screening range,” or “editorial preference” |
| Reference range | Versioned planning values with provenance and limitations | Approximate planning/comparison language only |
| Measured market observation | Retained raw observations, date, filters, source, sample count and published statistic | Median, quartiles or measured range only when the underlying release is auditable |
Technical and gemological research
We prioritize GIA and other primary or authoritative materials for grading terminology, diamond anatomy, laboratory processes, and statements about the limits of fancy-shape cut grading. Historical claims should use original or authoritative historical sources where practical.
Price observations
Diamond prices are not static. When we describe a number as a measured market observation rather than a general estimate, the update should record:
- observation date and currency;
- retailers or marketplaces sampled;
- natural or laboratory-grown status;
- carat band, color, clarity, grading-lab and other filters;
- number of qualifying listings;
- the statistic reported, such as median, range or quartiles;
- important exclusions and limitations.
The current Asscher Diamond Price Guide contains directional editorial ranges from its original edition. Because that edition did not preserve a complete auditable sample, we explicitly label those figures as estimates rather than presenting them as measured medians.
Retail inventory observations
Inventory depth can change daily. A statement that one retailer has more or fewer Asscher options should be treated as time-sensitive unless the observation date and comparable filters are documented. We do not treat a single screenshot or one browsing session as a permanent market fact.
Recommendations and preferred ranges
Asscher proportion, color, clarity and buying recommendations combine gemological principles with editorial screening judgment. We distinguish those preferences from formal laboratory standards. A range that works as a useful search filter is not the same thing as an official cut grade.
Source presentation
High-value guides should link to the specific source supporting a material claim rather than naming an institution generically. When a source does not support the full claim, we narrow the claim instead of stretching the citation.
Reproducibility checklist for measured data
- Retain the raw observation file used for the published result.
- Record the observation date, time zone, currency and source URL for each row.
- Define the cohort before calculating the statistic.
- State the number of included listings and any exclusions or deduplication rules.
- Keep natural and laboratory-grown diamonds separate unless a comparison explicitly calls for both.
- Publish the statistic actually calculated; do not relabel an editorial estimate as a measured median later.
Machine-readable source classifications are available in the source registry, and the blank price-observation template shows the fields required for a future market release.
Update standard
An “updated” date should reflect a substantive review of facts, data, recommendations, sources or page structure. Cosmetic edits alone should not be used to manufacture freshness.